angular2,post form to backend restful error:JSON输入的意外结束

时间:2016-12-01 12:22:24

标签: angular

我收到此错误:

accounts.service.ts?29fe:45 SyntaxError:JSON输入的意外结束。 它就像服务器不喜欢json格式。

当我使用Postman发送x-www-form_urlencoded两个字段时:lastname和firstname运行良好。

我不太清楚我必须要做的转换才能与后端一起工作,后端有x-www-form_urlencoded而另一个有完整的json?因为大多数教程都没有使用任何类型的转换来从表单发送帖子数据。 我见过一些使用新的URLSearchParams()的解决方案;但是在angular2中没有自动进行转换?

当我使用Postman发送帖子时,从我的服务器日志中获取:

add: {"lastname":"mylast","firstname":"myfirst"}

但是我得到了angular2组件:

add: {}

数据未到达

我有这个组件:

import {Component, Input, OnInit} from '@angular/core';
import {AccountsService} from '../shared/index';


@Component({
    selector: 'app-accounts-form',
    templateUrl: 'accounts-form.component.html',
    styles: [require('./accounts-form.component.scss')],
    providers: [AccountsService]

})
export class AccountsFormComponent implements OnInit {
    @Input() accountId: string = '';
    public account: any =       {
        firstname: '',
        lastname: ''
    };

    constructor(private accountsService: AccountsService    ) {
    }

    ngOnInit() {

        if (this.accountId !='' ) {
            this.getById();
        }
    }

    onSubmit() {
        if (this.accountId =='' ) {
            console.log('submit new');
            this.accountsService
                .insert(this.account)
                .subscribe((data) => {
                        console.log(data);
                        this.account = data
                    },
                    error => console.log(this.account),
                    () => console.log('Insert complete'));

        } else {
            console.log('submit update '+this.accountId);
        }

    }


    private getById(): void {

        this.accountsService
            .getById(this.accountId)
            .subscribe((data) => {
                    console.log(data);
                    this.account = data
                },
                error => console.log(this.account),
                () => console.log('Get Item complete'));


    }

}

模板:

<form (ngSubmit)="onSubmit()">
<div class="form-group">
  <label for="lastname">Last Name</label>
  <input [(ngModel)]="account.lastname"  name="lastname"/>
</div>
<div class="form-group">
  <label for="firstname">First Name</label>
  <input [(ngModel)]="account.firstname"  name="firstname"/>
</div>
<div>
  <button type="submit" class="btn btn-default"
          >Submit</button>
</div>
</form>

服务:

import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions } from '@angular/http';
import 'rxjs/add/operator/map'
import { Observable } from 'rxjs';
import { Configuration } from '../../app.constants';

@Injectable()
export class AccountsService {
  private actionUrl: string;
  private headers: Headers;

  constructor(private http: Http, private configuration: Configuration) {

      this.actionUrl = configuration.ServerWithApiUrl + 'accounts';

      this.headers = new Headers();
      this.headers.append('Content-Type', 'application/json');
            this.headers.append('Accept', 'application/json');
  }


    public insert(body: any): Observable<any> {
        console.log( 'insert url:'+ this.actionUrl  );
        console.log(JSON.stringify( body))
        return this.http.post(this.actionUrl , JSON.stringify( body),  { headers: this.headers })
            .map((response: Response) =>  response.json())
            .catch(this.handleError);
    }

  private handleError(error: Response) {
      console.error(error);
      return Observable.throw(error.json().error || 'Server error');
  }

}

我的后端服务器有mongo和express4:

const insert = function (req, res) {
    data = req.body;
    console.log('add: ' + JSON.stringify(data));
    objectDb.insertOne(data, function (err, result) {
        if (err) {
            res.send({'error': 'An error has occurred'});
        } else {
            res.send(result[0]);
        }
    });

};

我已尝试过我的服务,请不要使用表单值,而是使用&amp;;和json值,并且不起作用:

  1. 尝试使用&amp;

    发送数据

    返回this.http.post(this.actionUrl,&#39; firstname&amp; = test1&amp; lastname = test2&#39;,{header:this.headers})     .map((响应:响应)=&gt;响应)     .catch(this.handleError);

  2. 尝试使用json发送数据

    return this.http.post(this.actionUrl ,  {'firstname':'test1','lastname':'test2'},  { headers: this.headers })
        .map((response: Response) =>  response)
        .catch(this.handleError);
    
  3. 两种方法都不起作用

    更新:

    我已经更改了insert()我的服务:

    .map((response: Response) =>  response.json()) <-- removed .json() here;
    

    不再有错误:&#39; JSON输入的意外结束&#39;只是数据不会发送到服务器。

    我已更新以获取回复日志:

    .map((response: Response) => console.log(response))
    

    然后我得到了新的错误:

    core.umd.js?e2a5:2837 EXCEPTION: Error in ./AccountsFormComponent class AccountsFormComponent - inline template:3:9 caused by: Cannot read property 'lastname' of undefinedErrorHandler.handleError
    

    服务代码中实际更新的insert()函数:

    public insert(body: any): Observable<any> {
        console.log( 'insert url:'+ this.actionUrl  );
        console.log(JSON.stringify( body))
        return this.http.post(this.actionUrl ,  {'firstname':'test1','lastname':'test2'},  { headers: this.headers })
            .map((response: Response) => console.log(response))
            .catch(this.handleError);
    }
    

    on developper tool xhr tab我得到:

    Request URL:http://localhost:3000/accounts
    Request Method:POST
    Status Code:200 OK
    Remote Address:[::1]:3000
    Response Headers
    view source
    Access-Control-Allow-Origin:*
    Connection:keep-alive
    Content-Length:0
    Date:Thu, 01 Dec 2016 14:21:04 GMT
    X-Powered-By:Express
    Request Headers
    view source
    Accept:application/json
    Accept-Encoding:gzip, deflate, br
    Accept-Language:de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4,fr;q=0.2
    Connection:keep-alive
    Content-Length:40
    Content-Type:application/json
    Host:localhost:3000
    Origin:http://localhost:8080
    Referer:http://localhost:8080/accounts-add
    User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36
    Request Payload
    view source
    {firstname: "test1", lastname: "test2"}
    firstname
    :
    "test1"
    lastname
    :
    "test2"
    

1 个答案:

答案 0 :(得分:2)

您正试图将自己的身体贴为'application/json' ..

所以不要JSON.stringify()你的身体。